1. Field
One or more embodiments relate to a tilt-prop aircraft capable of switching between a vertical take-off and landing mode and a forward flight mode.
2. Description of the Related Art
Tilt-prop aircrafts are capable of switching between a vertical take-off and landing (hereinafter, also referred to as “VTOL”) mode and a forward flight mode. In general, a tilt-prop aircraft has rotors on left and right ends of a wing, which are configured to rotate in opposite directions. In this case, switching between flight modes is carried out by varying the angles of nacelles including the rotors. That is, if the rotation axes of the rotors are adjusted to be perpendicular to the ground, the rotors may function like rotors of helicopters such that vertical take-off and landing is possible, and if the rotation axes of the rotors are adjusted to be parallel with the ground, the rotors may function like propellers such that high-speed forward flight is possible. In this case, core technology is to convert the rotation axes of the rotors during flight.
When a tilt-prop aircraft operates in a forward flight mode, rotors are oriented in a forward direction, and since the velocity of relative wind entering the rotors increases as the velocity of flight increases, the pitch angles of blades should be largely increased to generate proper thrust. Therefore, additional control actuators may be required to finely adjust the pitch angles of the blades.
However, since electric actuators for adjusting a blade pitch angle and a rotor tilt angle are provided for each rotor, tilt-prop aircrafts of the related art are heavy in addition to having a complicated electric wiring system and consuming a large amount of electricity. In particular, the weight of a multicopter-type tilt-prop aircraft including a plurality of rotors is further increased because two control actuators are provided for each rotor.